Chapter 3
Transitions between neighboring energy levels take place due to the adsorption of
electromagnetic radiation of characteristic wave lengths at Larmor frequency. The
precession of spins at the same Larmor frequency is referred as coherent or
in-phase.
NMR is a versatile method because [1]: 1) It is not a destructive technique.
The system can be studied without any perturbation that will affect the outcomes
of the measurement. The system can be characterized repeatedly with no
time-consuming sample preparation in between runs. 2) A large number of
spectroscopic parameters can be determined by NMR relating to both static and
dynamic aspects of a wide variety of systems.
For water-in-diluted bitumen emulsions, several characteristics, such as
water content and drop size can be estimated by different NMR protocols.
3.2. T2 distribution from CPMG measurement
3.2.1. Introduction
Relaxation of spins net magnetization M in longitudinal direction and in
transverse plane can be expressed as [2]:
dMz^ Mz-M0z dM^ = _M^
dt T1 ’ dt T2 ’ J
Here Mz is equilibrium magnetization in longitudinal direction. Mz and Λ4xy are
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